Laminate (more commonly known as plastic laminate) is a product which has been used in this country for decades as a countertop surface or a veneer for numerous articles of furniture, cabinetry and other architectural features. Laminate flooring (also known as plastic laminate flooring) was first introduced in the United States around 1994 by the Swedish company Pergo AB. Its initial product line consisted of planks made of laminated wood which were approximately 8″ wide and 48″ long, and which came in an assortment of wood tone finishes. Since that time, many other companies (such as Formica Corporation and Wilsonart International) have manufactured plastic laminate, and it is now an exceedingly popular floor covering.
Laminate flooring consists of layers of different materials, generally wood and/or wood byproducts/composites, which include an upper plastic laminate layer. The plastic laminate layer can be made to look like materials such as wood, stone, marble and cork by various printing methods. The specific finish that the floor is to replicate is printed on a layer which is incorporated into the plastic laminate. The plastic laminate is then adhered to a substrate of wooden or wooden composite material. To make the finished surface durable, a tough wear layer is applied to the laminate surface.
Typically, the wear layer, laminate layer and substrate layer are produced in 4′ by 8′ sheets in a linear production line prior to their being resized into elongated plank-like flooring tiles. A sheet moves along a conveyor to different stations to be cut to the rough shape and size of the tiles. The sheet is often first cross-cut to produce two 4′ by 4′ sections, and is then gang-ripped to produce planks. The planks continue along the conveyor and are fed into a molder, which has a series of cutters set in a straight line array in order to profile a tongue along one side edge of the plank and a groove along the opposite side edge of the plank. The pieces are then rotated by means of the conveyor and are fed into the next machine, which adds a tongue to one end edge of the plank and a groove to the opposite end edge of the plank. The resulting planks are then suitable for installation on a floor (or other surface) by fitting a tongue of one plank into the groove of an adjacent plank.
Wood flooring is manufactured in much the same way, but solid wood flooring is generally not initially cut into standard-size larger sheets. Rather, it is milled into board widths determined by the girth of the tree from which they came. Engineered wood flooring is more similar to laminate flooring in that a surface layer or veneer of a wood species is adhered to a substrate of either plywood or a composite material, and such engineered wood flooring may be initially laid up in the 4′ by 8′ format. The machining process for engineered wood flooring is generally similar to that for laminate and wood flooring.
Manufacturing of the aforementioned tiles requires a surprising degree of precision. Tile thicknesses are of critical concern, since tiles that have out-of-tolerance thicknesses, or vertically offset tongues or grooves, generate “ledging”: one tile has an edge raised above the surface of an adjacent tile. Apart from being unsightly and potentially dangerous (particularly since upper wear surfaces are generally very tough and can provide a knife-like edge), ledging leads to rapid wear. This is why a tongue and groove or similar interlocking arrangement (such as splines, rabbeted joints, or embedded metal interlocks) is generally needed between laminate tiles; the interlocking arrangement, if properly situated on the tile edges, helps align the top surfaces of laminate tiles in coplanar relationship, even if adhesive is not uniformly applied to the bottoms of adjacent tiles. Additionally, since gaps between adjacent tiles can greatly diminish the appearance of the floor, tight dimensional tolerances must be observed in tile lengths and widths. Prefinished materials such as plastic laminate and wood veneers require a very tight tolerance, whereas installations that are sanded and finished—such as with wooden floors—the filler and finish help disguise any gaps related to milling (as well as gaps arising from swelling or contraction). Additionally, any ledging is removed through the sanding process.
An exception to the foregoing forms of manufacturing occurs with decorative elements, such as medallions and feature strips (also known as border strips), for wooden flooring. A medallion may include a predetermined design made up of differently shaped pieces of different types of wood. The pieces of the design are machined from thin layers of wood (usually no more than ⅛″ thick) with their edges perpendicular to the top and bottom surfaces so that they can be adjacently fitted together with no gaps. The pieces are adhered to a substrate which is then cut to the required shape, such as a square, rectangle, circle or ellipse. Thus, medallions are veneered tiles somewhat similar to engineered wood tiles, and the design pieces serve as a decorative top layer for the substrate. Borders are manufactured similarly, but generally use only squares and rectangles for their design pieces. Additionally, borders may include a tongue and groove edge to allow the linear mode of manufacturing. Medallions often do not have a tongue or groove around their edge, and can only be installed as a drop-in feature. In other words, after an entire floor has been installed, a hole can be cut through the installed floor (generally with a router) to accept the medallion, which is then glued in place. Decorative elements are mass produced, and various lines of elements are available in stores and catalogs for installation in wooden floors.
As of 2001, decorative elements such as borders and medallions are not known to be used with laminate floors. This is probably owing to several reasons. First, because they are made of different materials than the laminate floors (generally wood or wooden composites), their different appearance is difficult to coordinate with laminates, particularly if their finish changes with age. Second, since the laminates are much tougher, the more significant wear on the wood-based elements would make them stand out more over time. Third, laminates must be cut with great care so that their surfaces do not chip, or so that the laminate planks do not break (which may occur if hole-cutting unduly reduces the width of a laminate plank). This makes it inadvisable to cut holes in laminates to receive decorative elements, since chipping of the laminate floor may necessitate its removal and replacement if damage occurs. Fourth, laminates can be difficult to cut with precision owing to their toughness, making it difficult to cut a hole in a laminate floor which may tightly receive a decorative element. Fifth, unless a decorative element is made of laminate materials which is exceedingly difficult for the aforementioned reasons—the use of a decorative element with laminate floors can lead to gapping and ledging problems owing to different degrees of expansion/contraction between the materials owing to heat and humidity. Sixth, since the thicknesses of laminate floors vary by manufacturer, it would be exceedingly expensive to manufacture decorative elements for all different laminate flooring lines because of the wide variety of decorative elements that would be required. Variations in the widths and lengths of laminate planks generate similar difficulties. It is possible to create a border of sorts for laminate floors by using differently-colored planks (from the same manufacturer) adjacent the walls and bounding the remainder of the floor, but since such borders are uniformly colored—as opposed to commonly-used variegated border designs, such as checked and mosaic designs—these are rather drab. It is inadvisable to merely cut laminate planks into sections and arrange them into patterns, since the cutting will almost certainly eliminate some or all of the tongue-and-groove engagements between sections, and the interlocking arrangement between sections is needed to help avoid ledging and gaps. Additionally, the aforementioned problems with chipping and/or gaps arise.
It would therefore be useful to have available methods and apparata for producing decorative elements suitable for use with laminate floors, in particular decorative elements made of laminate material, which avoid or substantially reduce the aforementioned problems.